Process of agglomerating fine ores.



J. H. PAYNE. PROCESS OF AGGLOMERATING FINE ORBS.

APPLICATION FILED PEB.21, 1914.

amv/1mg s Patented Oct. 20, 1914.

w 4.1111 1km.

. A ull- 'which stop the op JAMES H. PAYNE, OF BALTIMORE, MARYLAND.

PROCESS 0F AGGLOMERATING FINE GRES.

Specication of Letters Patent.

Patented Oct. 20, 1914.

Application filed February 21, 1914. Serial No. 820,156.

To all whom tt may concern:

Be it known that I, JAMES I'I. PAYNE, a citizen of the United States, residing at Baltimore, in the State of Maryland, have invented or discovered certain new and useful Improvements in Processes of Agglomerating Fine Ores, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to the nodulizing of fine ores, containing considerable quantities of sulfur, which cannot be conveniently nodulized in accordance with the processes described in most of the prior patents on nodulizing, for the reason that the combustion of the large quantities of sulfur present generates a sufficient amount of heat to carry the temperature of the ore undertreatment to a point somewhat above that necessary for'the incipient fusion which produces the nodulizing.

In the well known ore nodulizing process, which consists in heating ore to the point of incipient fusion while it travels downwardly through an inclined rotating cylinder, care must be taken that the temperature of the ore does not appreciably exceed the point of incipient fusion becauseif this condition occurs the ore soon sticks to the wall of the furnace in such a hard crust as to soon choke the kiln, and further because when the ore becomes heated to too soft a state large unmanageable fused masses are produced eration of the process. In the nodulizing of certain classes of ore, particularly copper ores containing considerable quantitles of metal sulids, which ores are commonly referred to as copper bearing pyrites, and copper bearing pyrrhotite, the sulfur of the ore in burning is liable to produce this excessively high temperature above referred to, and it is vone of the objects v of the present invention to prevent the formation of this excessively high temperature by presentingl any material amount of combustion of t e sulfur of the ore. I have found that a convenient way of preventing the combustion of the sulfur, is by preventing the entrance of the air necessary for such combustion, thereby raintaining a Substantially non-oxidizing condition, which may or may not be actually reducing, with` in the rotating furnace, in which the process is being carried out. The admission of air in carryin out the present invention, is restricted su stantially to that which is neces- 'rying the nodulized ore sary for the combustion of the fuel injected at the lower end of the furnace.

In carrying out my process the apparatus shown by way of example in the annexed drawings may be employed.

In said drawings Figure 1 represents a vertical section of a furnace suitable for use in the process, with the necessary attachments thereto, and Fig. 2 represents a cross section of the apparatus shown in Fig. 1, Said. section being taken on the line 2-2 of Fig. 1, looking in the direction of the arrow.

In carrying out the'process in the apparatus shown, the ore may be introduced by means of a spout 4', at the upperlend of-a rotating furnace 5, which is interiorly provided with a lining of refractory fire-brick or the like 6, andwhich furnace may be caused to rotate by means of the gears 7 and `8, in the usual manner.

At the lower end of the furnace 5, I provide a hood 9, which fits closely against the end of the rotatingfurnace 5, suitable sand seals or the like being provided if necessary or desired,- in order to exclude the entrance of material quantities of air around the edges of the hood, or between the hood and the furnace 5. At 10 is shown a fuel inlet, and at 11 is shown an air inlet for reducing a substantially non-oxidizing 'iiarna for heatingx the ore to the nodulizing tempera ture, t e fuel and air inlet being provided with suitable valves 15 and 16, respectively, for regulation. v

The ore in gradually advancing from the spout 4 to theoutlet zend of the` furnace, becomes gradually heated to the-temperature necessary for nodulization, while the ex-V clusion ofair revents the combustion of the liberated sul ur, thereby preventing the over-heating which would cause partial liquefaction of the ore under treatment, that is, would prevent thel nodulization andv would cause the molten or Semi-molten ore to adhere to the walls of the furnace, which would either choke up the furnace or would form large unmanageable masses, fused. to-

ether, which would not readily discharge rom the thereby render the Same inoperative. At 12 is shown an outlet for the nodulized ore,

`which may be provided with a suitable valve 13, which remains closed when ore is coming out, discharges into a car or by gravity except and the outlet` 12 the. like 14, for carto a suitable blast lower end of the furnace, and

material nuisance to cinity of the works.

lcordingly add a fect good furnace or other used. Y

In .order to permit ready accessy to the interior of therotating kiln for periodically cleaning or repairing or the lilxe, the hood 9 is preferably mounted on small trucks so that it can be moved back when desired. l.

It ',willv be noted that While the flap valve v13 will be open during the discharge vof the material from the spout 12, the spout 12 itself at that time will be -full of ore device in which it is to be being discharged so that no material amounts of air can enter at this point.l

A considerable quantity of the sulfur of the ore may distil therefrom in the form of elemental sulfur, which may or may lnot be in suflicient quantities to recover in merchantable form, but whether the sulfur is recovered or not is rather immaterial in the fpresent process, which relates tothe nodulizationof ore, and not to the production of sulfur as its principal feature. Moreover the prevention of the combustion of the sulfur likewise prevents the formation of large quantities of sulfur dioxid which being discharged into the atmosphere would cause a A second diiiculty is often met with in the treatment of suld ores of the class herein referredf to, namely that the temperature of material even when heated s0 as to avoid oxidi'zation as above referred to, has only la very short range between the point ofi incipient fusion and the point of more or less complete fusion, and in certain cases, I acfusion retarding agent to the ore, as in my copending application N o. 760,260, lled April 10, l1 13. prior application add a suitable material to `prevent overfusion of themass of material, that is to say withores of an acid nature I may add silica or sand, Ywhile with ores of an alkaline 'nature I may add lime or the like, or in either case I'm'ay add a substance of which the decomposition is endothermic, such as calcium sulfate or the like, and it is of course under# stood, that in place of pure silica, pure lime, or pure calcium sulfate, I may employ ores containing copper or othery valuable metal, in which isalso contained the silica, lime, or calcium sulfate, or other material to be employed for the purpose of preventing over fusion.

While the step of preventing oxidation of the sulfur is in many cases sufficient to efnodulization of the sulli ores, I ndthat certain cases it is advisable to combine this step withthe addition of a retarding agent as above stated.

It is obvious that vvariousfuels may be used, such as. `gas,""oil, or powdered coal,

provided the.' :precaution is taken to burn them without a material excess of air in plant-life in the vilincipient fusion As in said above referred to, I may sulfur in the form of plied thereto,

order that the heated gases resulting may be practically free from oxidizing effect upon the sulfur of the ore.

Various modifications of other portions of the process may be made Without departing from the spirit of my invention.

Having thu's described my invention What I claim is:

1. A process of nodulizing ores containing sulfur in material amounts which comprises heating said ore to a point of incipient fusion While agitating the same, and While avoiding the presence of sufficient free oxygen to burn the sulfur of said ore, thereby avoiding over-fusion of the ore.

Y2. A processof treating ores containing material quantities of sulfur, which comprises heatinga stream of said ore, while agitating and rolling the particles thereof; introducing a flame of air and fuel in counter current with said stream lof ore, while preventing the entrance of suilicient air, over the amount necessary for the combustion of the fuel, to burn material quantities of the sulfur, and discharging the treated ore'at the lower end of the furnace.

3. A process of agglomerating, fine ores containing `material quantities of sulfur, vwhich comprises heating a continuous stream of said ore while ,agitating and rolling the particles thereof, introducing a flame of air and fuel in counter current to said stream of ore, while preventingV the entrance of suficient air, over the amount necessary for the combustion of the fuel, to burn material quantities of the sulfur, heating said ore'by means of said flame to the point of and discharging the resulting nodules at the lower end of the furnace.

LVA process of agglomerating fine ores containing material quantities of sulfur, which lcomprises nodulizing said ore While agitating and rolling the ore particles by applying heat practically devoid of oxidizing action upon the sulfur contained in the ore.

5. A process of nodulizing ore containing metal sulid, which comprises heating said ore, by a flame apto' a temperature sulicient for incipient fusion, agitating said ore during said heating operation, and avoiding contact of said ore with suflicient amounts of vfree oxygento burn the sulfur.

6. A process of nodulizing sulid ores, which comprises mixing therewith a substance capable of preventing over-fusion, heating said mixture to a nodulizing temperature, while avoiding the presence of free oxygen in amounts sufficient to burn material quantities of the sulfur content 0f said ore.l

7. A process of nodulizing suld ores, which comprises mixing .therewith a calcareous material for the purppse of prevent- -ing over-fusion, heating said mixture to a presence of free oxygen in amounts suiicient vto burn material quantities of thel sulfur content of said ore, and while rolling and agitating the ore particles.

c 8. A process of noduli'zing sulfid ores, which comprises mixing therewith a substance of which the decomposition is endothermic, heating said mixture to a nodulizing temperature, while avoiding the presence .of free oxygen in amounts suicient to burn material quantities of the sulfur content of said ore, and while rolling and agitating the ore particles.

9. A process of nodulizing sulfid ores, 15 which comprises mixing therewith calcium sulfate, heating said mixture to a nodulizing temperature, while avoiding the presence of free oxygen in amounts sufficient vto burn material quantities of the sulfur content of 20 said ore, and while rolling and agitating the ore particles.

In testimony7 whereof I aiix my signature, in presence of two witnesses.

JAMES H. PAYNE. Witnesses 

